Accident report: An attempt to land on one engine was made. Following a hard landing on one
wheel, full power was applied by the instructor because another aircraft had entered the runway. The engine failed on climb-out and the C-46 struck the mast of a ship, causing it to crash into the sea. No fatalities; occupants: instructor and student only.
Aircraft damaged beyond repair; written off. Source: Aviation Safety Network

________________________________________

(CB-541)

This C-46D was operated by the Corporacion Boliviana de
Fomento from 1946 until a fatal accident in 1962 when it was written off. As far as I can tell it was not used by LAB.

______________________________________

CP-730

A similar C-46F operated by Servicio Aereo Oriental

Curtiss C-46D-CU c/n 33457

History:

Built by Curtiss-Wright Corp. at Buffalo, NY
1944

USAAF
44-78061
24 Mar 1945

Reconstruction Finance Corp. "
Dec 1945

- wfu and stored at Walnut Ridge Army Air Field, AR

Transportes Aereos Universal - Brazil PP-BBC
1 May 1948

Ferris and Buarque Corp - Brazil "
17 May 1952

Loide Aereo Nacional - Brazil PP-LDN
19 May 1952

Transportes Aereos Bandeirantes PP-BLD
5 May 1958

-
? this company merged with Loide in 1950

Aerovias Condor - Bolivia CP-730
Sep 1963

LAB "
1965

- leased from Aerovias Condor (they ceased operations in 1963)

Accident between Riberalta and Cochabamba
3 Aug 1966

- sometimes listed as 8 Mar 1966

Accident Report:

After a normal flight from La Paz to Riberalta, CP-730 took off for Cochabamba at 1130.35 hrs. Bolivian time, to carry out the second part of its flight plan, a special cargo flight. The only persons on board were
the three crew members. The aircraft reported over Santa Ana and San Ignacio at 1232 hrs. and 1255 hrs. respectively, and estimated the next contact with Cochabamba control at 1340 hrs, when it would be over Rio Juntas, 20 min. away from its destination.

At 1345 hrs. Cochabamba control called CP-730 requesting a new estimate over Rio Juntas. No reply from the aircraft was received and Cochabamba requested Trinidad control to try and contact the aircraft. As no message had been received
from CP-730 by 1400 hrs, blind transmissions were sent out of weather conditions in the mountains, on the assumption that the aircraft's radio transmitter was not operating; in addition all stations in the area were warned to expect a possible landing of the
aircraft. Since by 1440 hrs. no landing of the aircraft was reported, an ALERFA was declared [the alert phase of an emergency where apprehension exists concerning an aircraft and its occupants], followed later at 1540 hrs. by a DETRESFA [distress phase - reasonable
certainty that an aircraft and its occupants are threatened by grave and imminent danger or require immediate assistance].

Search operations were initiated at 1700 hrs. and continued for nine days over an area of 169,000 square miles
without success. Twelve days after CP-730's disappearance, two peasants reported in [a town near] Cochabamba that while out hunting in the mountains they had found the missing aircraft and brought two pieces of aluminum from it as proof. On the
strength of this evidence that CP-730 had been located, investigation teams were assembled and arrived at the site of the accident thirteen days after its occurrence.

The three Bolivian crew members did not survive.

The wreckage of the aircraft was distinguishable only from 40 m (120 ft) away because of ice which had formed on it and the configuration of the terrain; this explains why the aerial search was unsuccessful.

Analysis:

A pilot who had flown the same route as CP-730 in a C-46 which arrived at Cochabamba at 1400 hrs. reported that there was a strong tailwind
and that weather conditions had necessitated instrument flight.

A DC-3 that had also taken the same route reached Cochabamba shortly after 1400 hrs, 25 min. ahead of its ETA owing to the tailwind.

From
the foregoing it can be deduced that CP-730 was beyond its estimated position because of the strong tailwind. This would explain why the pilot flying in IMC [instrument meteorological conditions] and convinced that he had not yet reached Rio Juntas, failed
to report over this point and unexpectedly found himself in the mountains.

Conclusion:

Due to a tailwind the aircraft was beyond its estimated position, The pilot did not report over Rio Juntas and unexpectedly found himself in the mountains. In an attempt to fly clear of the mountains he made a 90 degree
turn to the right and struck the ground.

-This very thorough report was issued in 1971 by the International Civil Aviation Organization and was part of its Aircraft Accident Digest No. 18, Vol. 2.